Yellow weather warnings for rain have been issued for the south of England and Wales with persistent heavy showers expected to cause flooding and travel disruption.
The first weather warning covers the length of the south of England and much of southern Wales.
The warning is in place until 11.45pm on Thursday meaning there is a risk of flooding, road closures, difficult driving conditions causing increased traffic and flooded roads. On Friday, a similar the warning is in place for coastal areas of Wales and southern England running throughout the entirety of tomorrow.
There is a slight chance of power cuts and a small chance of some communities being cut off by flooded roads and deep floodwater causing a danger to life, the warning states.
Multiple areas, including areas not necessarily included in the weather warning could see up to 50-60mm of rain over a long period on Thursday afternoon.
Met Office meteorologist Clare Nasir added said the heavy rain expected “will be waxing and waning but one or two spots could see up to around 100mm over 48 hours.”
Patchy rain will also occur in the the north east of England on Thursday.
The day will be dry and bright elsewhere with humid conditions for many, although eastern areas are expected to be windy.
Temperatures will settle at 20°C in the south and the high teens across the north, with Newcastle and Edinburgh seeing highs of 15°C and 16°C respectively.
Commuters and motorists have been warned to expect spray and sudden flooding, leading to difficult driving conditions and some road closures.
The north of England, Northern Ireland and Scotland are expected to see fine, dry sunny weather leading into the weekend, although the far north west may see some patches of rain.
Nasir continued: “On Friday we could see some high temperatures across western and central parts of Scotland, 25°C or 26°C”
Saturday is forecast to remain unsettled with outbreaks of rain, some of it heavy across the south into Sunday before turning showery with brighter spells.
South Western Railway said the forecast may see trains running at reduced speed on Thursday between Axminster and Honiton in Devon, with some services possibly altered, following a landslip at Honiton Tunnel earlier in the year.
Looking further ahead, the Met Office has said the UK is not heading for a record-breaking September heatwave.
Some reports have predicted highs of 29°C to 30°C, with temperatures soaring past the current September record (currently 35.6°C in Yorkshire in 1906). Ladbrokes gave the odds that this month would be the hottest September on record 3/1.
But the Met Office has refuted the claims and said “there is no real indication of any prolonged heat across the UK at the moment”.